The inventor of the present invention has previously invented several chairs of the general type to which the present invention relates. One feature of those prior chairs is the provision of a backrest that tilts rearwardly from an upright position, in which it is normally held by spring-biased backrest mount mechanisms. One may refer, for example, to Ambasz European Patent Application No. EP 1 060 695 A2 (Dec. 20, 2000) for a description and drawings of a stackable chair having a tiltable backrest. Such chairs allow a user to change his or her position from upright to leaning back, which makes them more comfortable than chairs with fixed backrests.
Stackable institutional chairs often have ganging fittings, connectors that permit the chairs to be joined together side by side. When the chairs have armrests, the provision of ganging fittings, which protrude from the sides of the chairs, prevents dense stacking the chairs, inasmuch as the arms of a lower chair will not allow the ganging fittings of an upper chair to pass. Ambasz Published International Application No. WO 00/24294 (Oct. 22, 1999) reveals one solution to that problem—the armrest is mounted so that it can be pivoted outwardly from a use position to a storage position in which the arm allows the ganging fitting to pass downwardly.